... Sun . ... Observing . ... Voyager celebrates 25 years since Uranus visit . ... After completing its prime mission of flying by Jupiter and Saturn, Voyager 2 was sent on the right flight path to visit Uranus, which is about 2 billion miles (3 billion kilometers) away from the Sun. ... Before Voyager 2's visit, scientists had to learn about Uranus by using Earth-based and airborne telescopes. By observing dips in starlight as a star passed behind Uranus, scientists knew Uranus had nine narrow rings. ...